JP4835594B2 - Secondary battery - Google Patents

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JP4835594B2
JP4835594B2 JP2007539394A JP2007539394A JP4835594B2 JP 4835594 B2 JP4835594 B2 JP 4835594B2 JP 2007539394 A JP2007539394 A JP 2007539394A JP 2007539394 A JP2007539394 A JP 2007539394A JP 4835594 B2 JP4835594 B2 JP 4835594B2
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electrode plate
positive electrode
negative electrode
current collector
exposed portion
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JPWO2007142040A1 (en
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きよみ 神月
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Panasonic Corp
Panasonic Holdings Corp
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Panasonic Corp
Matsushita Electric Industrial Co Ltd
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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/64Carriers or collectors
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/64Carriers or collectors
    • H01M4/70Carriers or collectors characterised by shape or form
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/02Details
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/04Construction or manufacture in general
    • H01M10/0431Cells with wound or folded electrodes
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/058Construction or manufacture
    • H01M10/0587Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50Current conducting connections for cells or batteries
    • H01M50/531Electrode connections inside a battery casing
    • H01M50/538Connection of several leads or tabs of wound or folded electrode stacks
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/463Separators, membranes or diaphragms characterised by their shape
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50Manufacturing or production processes characterised by the final manufactured product

Description

本発明は、高出力化を図った二次電池に関し、特に低抵抗で大電流充放電に適した集電構造に関する。   The present invention relates to a secondary battery with high output, and more particularly to a current collection structure suitable for high current charge / discharge with low resistance.

近年、各種電気機器の小型・軽量化に伴い、その駆動電源となる二次電池が重要なキーデバイスの一つとして、その開発が進められている。その中でも、ニッケル水素蓄電池やリチウムイオン二次電池などの二次電池は、軽量、小型で高エネルギー密度であることから、携帯電話を始めとして民生用機器から電気自動車や電動工具の駆動用電源など各種用途に展開されている。最近では、特に、リチウムイオン二次電池が駆動用電源として注目され、高容量化・高出力化に向けて、開発が活発化している。   In recent years, with the reduction in size and weight of various electric devices, a secondary battery as a driving power source has been developed as one of important key devices. Among them, secondary batteries such as nickel metal hydride storage batteries and lithium-ion secondary batteries are lightweight, compact, and have high energy density, so power supplies for driving electric vehicles and power tools from consumer devices such as mobile phones It is deployed in various applications. Recently, in particular, lithium ion secondary batteries have been attracting attention as driving power sources, and development has been actively promoted toward higher capacity and higher output.

駆動用電源として用いられる電池には、大きな出力電流と大きな電池容量が要求され、電池構造、特に集電構造に工夫を加えた電池が提案されている。   A battery used as a driving power source is required to have a large output current and a large battery capacity, and a battery having a contrivance for a battery structure, particularly a current collecting structure, has been proposed.

例えば、大きな出力電流を得るために電極面積を大きくできる、正極集電体に正極合剤を塗布した正極板と負極集電体に負極合剤を塗布した負極板とをセパレータを介して対向させて捲回した電極群構成が用いられる。そして、この電極群を一方の電池端子を兼ねる円筒状の電池容器に収納し、電池容器の開口部は他方の電池端子を兼ねる封口板で封口することで二次電池が作製される。一般に、負極集電体は電池容器に、正極集電体は封口板に、それぞれ直接あるいは集電板、集電タブやリード板などの集電部材を介してできるだけ接続抵抗を小さくして電気的に接続されている。   For example, to obtain a large output current, the electrode area can be increased, and a positive electrode plate coated with a positive electrode mixture on a positive electrode current collector and a negative electrode plate coated with a negative electrode mixture on a negative electrode current collector are opposed to each other through a separator. A wound electrode group configuration is used. The electrode group is housed in a cylindrical battery container that also serves as one battery terminal, and the opening of the battery container is sealed with a sealing plate that also serves as the other battery terminal, whereby a secondary battery is manufactured. In general, the negative electrode current collector is electrically connected to the battery container, and the positive electrode current collector is electrically connected to the sealing plate, either directly or via a current collecting member such as a current collecting plate, a current collecting tab or a lead plate. It is connected to the.

また、二次電池を高容量化するためには、正極合剤および負極合剤の量を増加させるために各集電体の占める容積はできるだけ小さくすることが必要である。そのため、各集電体に、厚さが10数μm程度の薄い金属箔が用いられている。   Further, in order to increase the capacity of the secondary battery, it is necessary to make the volume occupied by each current collector as small as possible in order to increase the amount of the positive electrode mixture and the negative electrode mixture. For this reason, a thin metal foil having a thickness of about several tens of μm is used for each current collector.

さらに、各集電体と電池容器あるいは封口板との接続には、低抵抗でかつ正極板、負極板の全面に亘り均一に電流を流すとともに、電池内に占める接続部分の容積をできるだけ小さくする集電構造が必要である。   Furthermore, the current collector is connected to the battery container or the sealing plate with a low resistance, and a current flows uniformly over the entire surface of the positive electrode plate and the negative electrode plate, and the volume of the connecting portion in the battery is made as small as possible. A current collecting structure is required.

従来、このような要求を満たす集電構造として、図10、図11Aと図11Bに示すようなタブレス構造を有する二次電池が開示されている(例えば、特許文献1参照)。   Conventionally, a secondary battery having a tabless structure as shown in FIG. 10, FIG. 11A and FIG. 11B has been disclosed as a current collecting structure satisfying such requirements (see, for example, Patent Document 1).

すなわち、図10に示すように二次電池は、正極板51の正極合剤未塗工部51aに正極集電部材60を溶接し、負極板52の負極合剤未塗工部52aに負極集電部材61を溶接して電池容器62に内装されている。そして、負極集電部材61を電池容器62の内底部に、正極集電部材60を封口板63に接続したタブレス構造を有するものである。   That is, as shown in FIG. 10, in the secondary battery, the positive electrode current collecting member 60 is welded to the positive electrode mixture uncoated portion 51 a of the positive electrode plate 51 and the negative electrode mixture uncoated portion 52 a of the negative electrode plate 52 is welded. The electric member 61 is welded to be embedded in the battery container 62. And it has the tabless structure which connected the negative electrode current collection member 61 to the inner bottom part of the battery container 62, and the positive electrode current collection member 60 to the sealing board 63. FIG.

そのため、図11Aに示す正極板51や図11Bに示す負極板52には、幅方向の一端の長手方向にそれぞれ正極合剤未塗工部51aおよび負極合剤未塗工部52aを形成している。そして、正極板51と負極板52の各正極合剤未塗工部51a、負極合剤未塗工部52aは反対方向に配置して、例えば上下方向にずらしてセパレータ53を介して捲回し、セパレータ53から各正極合剤未塗工部51a、負極合剤未塗工部52aは突出させて電極群を構成している。ここで、正極合剤未塗工部とは正極板の正極集電体の露出部であり、負極合剤未塗工部とは負極板の負極集電体の露出部を意味する。   For this reason, the positive electrode plate 51 shown in FIG. 11A and the negative electrode plate 52 shown in FIG. 11B are respectively formed with a positive electrode mixture uncoated portion 51a and a negative electrode mixture uncoated portion 52a in the longitudinal direction of one end in the width direction. Yes. And each positive electrode mixture uncoated part 51a of the positive electrode plate 51 and the negative electrode plate 52 and the negative electrode mixture uncoated part 52a are arranged in opposite directions, for example, shifted in the vertical direction and wound through the separator 53, Each positive electrode mixture uncoated portion 51a and negative electrode mixture uncoated portion 52a protrude from the separator 53 to constitute an electrode group. Here, the positive electrode mixture uncoated portion is an exposed portion of the positive electrode current collector of the positive electrode plate, and the negative electrode mixture uncoated portion means an exposed portion of the negative electrode current collector of the negative electrode plate.

さらに、上記で構成された電極群を外周部から捲回軸心側に向けて順次折り曲げて各正極集電部材60、負極集電部材61と当接する面を形成し、この面に各正極集電部材60、負極集電部材61を溶接する構造である。   Further, the electrode group configured as described above is sequentially bent from the outer peripheral portion toward the winding axis to form a surface that contacts each positive electrode current collecting member 60 and negative electrode current collecting member 61, and each positive electrode current collector is formed on this surface. The electric member 60 and the negative electrode current collecting member 61 are welded.

これにより、正極板51および負極板52における電流分布が均一になり、充放電特性が向上するとしている。   Thereby, the current distribution in the positive electrode plate 51 and the negative electrode plate 52 becomes uniform, and charge / discharge characteristics are improved.

しかしながら、高容量化を実現するために集電体に薄い箔を用いた場合には、十分な機械的強度が得られない。そのため、特許文献1に開示されている各集電体の露出部端を順次折り曲げて集電部材と溶接する構造では、集電体は均一に折れ曲がらず、合剤塗工部に生じる歪により合剤の集電体からの剥離や破損が生じるという課題があった。   However, when a thin foil is used for the current collector to realize a high capacity, sufficient mechanical strength cannot be obtained. Therefore, in the structure where the exposed portion end of each current collector disclosed in Patent Document 1 is sequentially bent and welded to the current collector member, the current collector is not uniformly bent, and is caused by the distortion generated in the mixture coating portion. There was a problem that peeling and breakage of the mixture from the current collector occurred.

そこで、図12Aと図12Bに示すように、正極板71の正極合剤未塗工部71aおよび負極板72の負極合剤未塗工部72aを幅方向に沿って折り畳んで形成することで、機械的な強度を向上させた構成の集電構造が開示されている(例えば、特許文献2参照)。   Therefore, as shown in FIGS. 12A and 12B, by forming the positive electrode mixture uncoated portion 71a of the positive electrode plate 71 and the negative electrode mixture uncoated portion 72a of the negative electrode plate 72 by folding along the width direction, A current collecting structure having an improved mechanical strength is disclosed (for example, see Patent Document 2).

しかしながら、特許文献2に開示されている正極合剤未塗工部および負極合剤未塗工部を折り畳んだ集電構造では、折り畳んで厚みを増した部分の機械的な強度は向上するが、合剤塗工部と合剤未塗工部の境界部の厚みは変わらない。そのため、境界部においては、依然として荷重に対して機械的な強度が弱く、合剤塗工部との境界で折れ曲がる。その結果、合剤塗工部に歪が発生し、集電体から剥離するなどの課題があった。   However, in the current collector structure in which the positive electrode mixture uncoated portion and the negative electrode mixture uncoated portion disclosed in Patent Document 2 are folded, the mechanical strength of the portion where the thickness is increased by folding is improved. The thickness of the boundary portion between the mixture-coated portion and the mixture-uncoated portion does not change. Therefore, the mechanical strength is still weak against the load at the boundary, and it is bent at the boundary with the mixture coating portion. As a result, distortion occurred in the mixture coating portion, and there were problems such as peeling from the current collector.

なお、本明細書中においては、正極板と負極板とを独立して示す必要がない場合には、単に極板、合剤塗工部、合剤未塗工部(露出部)、集電体、集電部材のように記す場合がある。
特開2000−323117号公報 特開平4−324248号公報
In addition, in this specification, when it is not necessary to show a positive electrode plate and a negative electrode plate independently, an electrode plate, a mixture coating part, a mixture uncoated part (exposed part), a current collector Body, current collector member.
JP 2000-323117 A JP-A-4-324248

本発明の二次電池は、正極板および負極板の少なくとも一方の一端に設けた集電体の露出部が多孔質絶縁層から突出するように、正極板と負極板と多孔質絶縁層とが配置された電極群と、正極板および負極板に接続される集電部材と、集電体の露出部の位置に設けた集電体の露出部の幅より小さい折れ曲がり防止部と、を少なくとも有する構成としたものである。   The secondary battery of the present invention comprises a positive electrode plate, a negative electrode plate, and a porous insulating layer so that an exposed portion of a current collector provided at one end of at least one of the positive electrode plate and the negative electrode plate protrudes from the porous insulating layer. And at least a current collecting member connected to the positive electrode plate and the negative electrode plate, and a bending prevention portion smaller than the width of the exposed portion of the current collector provided at the position of the exposed portion of the current collector. It is a configuration.

この構成により、電極群から突出させた集電体の露出部の強度を向上でき、集電部材の接続時に生じる荷重などによる不均一な折れ曲がりを防止して、信頼性の高いタブレス構造が得られる。また、集電体からの合剤の剥離を防止するとともに、信頼性の高いタブレス構造を実現することにより大電流での充放電を実現した二次電池が得られる。   With this configuration, the strength of the exposed portion of the current collector protruding from the electrode group can be improved, and non-uniform bending due to a load generated when the current collecting member is connected can be prevented, and a highly reliable tabless structure can be obtained. . In addition, a secondary battery that prevents charging of the mixture from the current collector and realizes charging and discharging with a large current by realizing a highly reliable tabless structure can be obtained.

以下、本発明の実施の形態について、図面を参照しながら説明する。なお、二次電池として、リチウムイオン電池などの非水電解質二次電池を例に説明する。また、本発明は、本明細書に記載された基本的な特徴に基づく限り、以下に記載の内容に限定されるものではない。   Hereinafter, embodiments of the present invention will be described with reference to the drawings. As the secondary battery, a non-aqueous electrolyte secondary battery such as a lithium ion battery will be described as an example. Further, the present invention is not limited to the contents described below as long as it is based on the basic characteristics described in the present specification.

(実施の形態1)
図1Aは本発明の実施の形態1における二次電池の概略断面図であり、図1Bは図1AのB部拡大図、図1Cは図1AのC部拡大図である。また、図2Aは同実施の形態で用いる正極板の展開図で、図2Bは同実施の形態で用いる負極板の展開図である。
(Embodiment 1)
1A is a schematic cross-sectional view of a secondary battery according to Embodiment 1 of the present invention, FIG. 1B is an enlarged view of a portion B in FIG. 1A, and FIG. 1C is an enlarged view of a portion C in FIG. 2A is a development view of the positive electrode plate used in the embodiment, and FIG. 2B is a development view of the negative electrode plate used in the embodiment.

図1Aから図1Cにおいて、円筒型の非水電解質二次電池(以下、「電池」と記す)は、例えばアルミニウム箔からなる正極集電体に正極合剤が塗工された正極板1と、例えば銅箔からなる負極集電体に負極合剤が塗工された負極板2と、正極板1と負極板2間に、例えば厚み25μmのポリプロピレン樹脂製の微多孔フィルムからなる多孔質絶縁層(以下、「セパレータ」と記す)3を配して渦巻き状に捲回された電極群4を備えている。   1A to 1C, a cylindrical nonaqueous electrolyte secondary battery (hereinafter referred to as “battery”) includes a positive electrode plate 1 in which a positive electrode mixture is applied to a positive electrode current collector made of, for example, an aluminum foil; For example, a negative electrode plate 2 in which a negative electrode mixture is coated on a negative electrode current collector made of copper foil, and a porous insulating layer made of a microporous film made of polypropylene resin having a thickness of 25 μm, for example, between the positive electrode plate 1 and the negative electrode plate 2 (Hereinafter referred to as “separator”) 3 is provided with an electrode group 4 wound in a spiral shape.

ここで、正極板1は、図2Aに示すように正極集電体の幅方向の一端から長手方向に帯状に設けられた正極合剤未塗工部5aと正極合剤塗工部5bが設けられている。   Here, as shown in FIG. 2A, the positive electrode plate 1 is provided with a positive electrode mixture uncoated portion 5a and a positive electrode mixture coated portion 5b provided in a band shape in the longitudinal direction from one end in the width direction of the positive electrode current collector. It has been.

また、負極板2は、図2Bに示すように負極集電体の幅方向の一端から長手方向に帯状に設けられた負極合剤未塗工部6aと負極合剤塗工部6bが設けられている。なお、正極合剤未塗工部5aおよび負極合剤未塗工部6aとは、正極集電体および負極集電体が露出した、各集電体の露出部を示したものであり、理解を助けるために別の表現で表している。   Further, the negative electrode plate 2 is provided with a negative electrode mixture uncoated portion 6a and a negative electrode mixture coated portion 6b provided in a strip shape in the longitudinal direction from one end in the width direction of the negative electrode current collector as shown in FIG. 2B. ing. In addition, the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a are the exposed portions of each current collector in which the positive electrode current collector and the negative electrode current collector are exposed. It is expressed in different expressions to help.

このとき、電極群4は、少なくとも正極板1の正極合剤塗工部5bと負極板2の負極合剤塗工部6bの間に介在するセパレータ3を介して、その幅方向において正極合剤未塗工部5aと負極合剤未塗工部6aが互いに反対方向にセパレータ3の端縁から突出した状態で捲回されている。   At this time, the electrode group 4 has at least a positive electrode mixture in the width direction via the separator 3 interposed between the positive electrode mixture coating portion 5b of the positive electrode plate 1 and the negative electrode mixture coating portion 6b of the negative electrode plate 2. The uncoated portion 5a and the negative electrode mixture uncoated portion 6a are wound in a state of protruding from the edge of the separator 3 in opposite directions.

そして、電極群4の捲回軸心の中心部には、例えば樹脂製の内径保持部材7を有し、捲回された電極群4の外周には、セパレータ3から突出した正極合剤未塗工部5aと負極合剤未塗工部6aの位置を規制するリング体8が嵌め込まれている。さらに、内径保持部材7とリング体8の間で捲回された正極合剤未塗工部5aおよび負極合剤未塗工部6aの中間部には、少なくとも後述する正極集電部材および負極集電部材の下面位置に配した、例えば図3Aと図3Bに示すU字やV字などの楔状の形状のばね材9を備えている。   A central portion of the winding axis of the electrode group 4 has an inner diameter holding member 7 made of, for example, resin, and the outer periphery of the wound electrode group 4 is not coated with a positive electrode mixture protruding from the separator 3. A ring body 8 for restricting the positions of the work part 5a and the negative electrode mixture uncoated part 6a is fitted. Furthermore, at least the positive electrode current collecting member and the negative electrode current collector, which will be described later, are provided in the intermediate portion between the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a wound between the inner diameter holding member 7 and the ring body 8. For example, a spring material 9 having a wedge shape such as a U-shape or a V-shape shown in FIGS. 3A and 3B is provided at the lower surface position of the electric member.

ここで、ばね材9としては、弾性力と耐薬品性に優れたポリカーボネート樹脂などの樹脂製のばね材が好ましい。また、金属製のばね材9を用いる場合には、正極板の集電体が露出した正極合剤未塗工部にはアルミニウム製のばね材が、負極板の集電体が露出した負極合剤未塗工部には銅、ニッケル製のばね材が、正極板および負極板との反応性が低く、かつ高い導電性を有しているので好ましい。   Here, the spring material 9 is preferably a resin spring material such as polycarbonate resin having excellent elasticity and chemical resistance. In addition, when the metal spring material 9 is used, the aluminum spring material is exposed to the negative electrode composite in which the current collector of the negative electrode plate is exposed in the positive electrode mixture uncoated portion where the current collector of the positive electrode plate is exposed. A spring material made of copper or nickel is preferable in the agent-uncoated portion because it has low reactivity with the positive electrode plate and the negative electrode plate and high conductivity.

なお、内径保持部材7、リング体8とばね材9の高さは、正極合剤未塗工部5aおよび負極合剤未塗工部6aの幅よりも小さいことが重要である。この理由は、高さが高いと、各集電部材と接続することができないためである。   In addition, it is important that the height of the inner diameter holding member 7, the ring body 8, and the spring material 9 is smaller than the widths of the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a. This is because if the height is high, it cannot be connected to each current collecting member.

そして、電極群4の正極合剤未塗工部5aおよび負極合剤未塗工部6aの少なくともばね材9の配置された位置に正極集電部材10および負極集電部材11を溶接し電気的に接続する。ここで、集電体と集電部材の溶接には、例えばアーク溶接(TIG(Tungsten Inert Gas)溶接法)、レーザ溶接法または電子ビーム溶接法を用いることができる。さらに、正極集電部材10および負極集電部材11を備えた電極群4を電池容器12に内蔵し、負極集電部材11を電池容器の底部に、正極集電部材10を絶縁板13の間に設けて封口板14と接続する。そして、電池容器12に非水電解質を注入し、ガスケット15を介して封口板14をかしめる。   Then, the positive electrode current collecting member 10 and the negative electrode current collecting member 11 are welded to at least the positions where the spring material 9 is disposed in the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a of the electrode group 4. Connect to. Here, for example, arc welding (TIG (Tungsten Inert Gas) welding method), laser welding method, or electron beam welding method can be used for welding the current collector and the current collecting member. Furthermore, the electrode group 4 including the positive electrode current collecting member 10 and the negative electrode current collecting member 11 is built in the battery container 12, the negative electrode current collecting member 11 is disposed at the bottom of the battery container, and the positive electrode current collecting member 10 is disposed between the insulating plates 13. And is connected to the sealing plate 14. Then, a nonaqueous electrolyte is injected into the battery container 12 and the sealing plate 14 is caulked through the gasket 15.

上記構成により、正極合剤未塗工部および負極合剤未塗工部がそれぞれ、内径保持部材7、リング体8およびばね材9で位置や高さを規制しながら位置が集合して、機械的な強度を向上させた二次電池が得られる。   With the above configuration, the positive electrode mixture uncoated portion and the negative electrode mixture uncoated portion are gathered while the position and height are regulated by the inner diameter holding member 7, the ring body 8, and the spring material 9, respectively. A secondary battery with improved strength can be obtained.

本発明の実施の形態1によれば、正極合剤未塗工部で示す正極集電体および負極合剤未塗工部で示す負極集電体と、正極集電部材および負極集電部材との接続時に生じる折れ曲がりを防止し、均一な接続が得られる。また、内径保持部材、リング体およびばね材により電極群の高さを一定にすることができるため、均一な電池特性を有する二次電池を生産性よく実現できる。   According to Embodiment 1 of the present invention, the positive electrode current collector shown by the positive electrode mixture uncoated part and the negative electrode current collector shown by the negative electrode mixture uncoated part, the positive electrode current collecting member, and the negative electrode current collecting member, Therefore, it is possible to prevent the bending that occurs at the time of connection, and to obtain a uniform connection. Moreover, since the height of the electrode group can be made constant by the inner diameter holding member, the ring body, and the spring material, a secondary battery having uniform battery characteristics can be realized with high productivity.

ここで、正極集電体は、金属製の薄い箔からなるアルミニウムの箔や穿孔体などを用いることができる。また、正極集電部材は、アルミニウムなどが用いられる。   Here, as the positive electrode current collector, an aluminum foil or a perforated body made of a thin metal foil can be used. Moreover, aluminum etc. are used for a positive electrode current collection member.

そして、正極合剤は、正極活物質、導電剤や結着剤からなる。具体的には、正極活物質としては、コバルト酸リチウム、ニッケル酸リチウム、マンガン酸リチウムなどの複合酸化物やそれらの変性体などを用いることができる。変性体として、アルミニウム、マグネシウムなどの元素を含有させることができる。また、コバルト、ニッケルおよびマンガン元素を混合して含有させることもできる。導電剤としては、正極電位下で安定な黒鉛・カーボンブラック・金属粉末などが用いられる。さらに、結着剤としては、正極電位下で安定なポリフッ化ビニリデン(PVDF)・ポリテトラフルオロエチレン(PTFE)などが用いられる。   The positive electrode mixture includes a positive electrode active material, a conductive agent, and a binder. Specifically, as the positive electrode active material, composite oxides such as lithium cobaltate, lithium nickelate, and lithium manganate, and modified products thereof can be used. As a modified body, elements such as aluminum and magnesium can be contained. Further, cobalt, nickel and manganese elements can be mixed and contained. As the conductive agent, graphite, carbon black, metal powder or the like that is stable under the positive electrode potential is used. Furthermore, as the binder, polyvinylidene fluoride (PVDF) / polytetrafluoroethylene (PTFE) which is stable under a positive electrode potential is used.

一方、負極集電体は、金属製の薄い箔からなる銅箔や銅穿孔体などを用いることができる。また、負極集電部材は、ニッケル、銅や銅/ニッケルめっきなどが用いられる。   On the other hand, the negative electrode current collector can be a copper foil or a copper perforated body made of a thin metal foil. Moreover, nickel, copper, copper / nickel plating, etc. are used for a negative electrode current collection member.

そして、負極合剤は、負極活物質、導電剤や結着剤からなる。具体的には、負極活物質としては、天然黒鉛、人造黒鉛、アルミニウムやそれを主体とする種々の合金、酸化スズなどの金属酸化物や金属窒化物を用いることができる。また、導電剤としては、負極電位下で安定な黒鉛・カーボンブラック・金属粉末などが用いられる。さらに、結着剤としては、負極電位下で安定なスチレン−ブタジエン共重合体ゴム(SBR)・カルボキシメチルセルロース(CMC)などが用いられる。   And a negative electrode mixture consists of a negative electrode active material, a electrically conductive agent, and a binder. Specifically, as the negative electrode active material, natural graphite, artificial graphite, aluminum, various alloys mainly composed thereof, metal oxides such as tin oxide, and metal nitrides can be used. As the conductive agent, graphite, carbon black, metal powder, etc. that are stable under a negative electrode potential are used. Further, as the binder, styrene-butadiene copolymer rubber (SBR) / carboxymethyl cellulose (CMC) which is stable under a negative electrode potential is used.

また、非水電解質としては、非水電解液やポリマー材料に非水電解液を含ませたゲル電解質を用いられる。そして、非水電解液は非水溶媒、溶質や添加剤とからなる。溶質として、六フッ化リン酸リチウム(LiPF6)、四フッ化ホウ酸リチウム(LiBF4)などのリチウム塩が用いられる。非水溶媒としては、エチレンカーボネート、プロピレンカーボネートなどの環状カーボネート類や、ジメチルカーボネート、ジエチルカーボネートおよびエチルメチルカーボネートなどの鎖状カーボネート類などを用いることが好ましいが、これらに限定されるものではない。なお、非水溶媒は、1種を単独で用いてもよいが、2種以上を組み合わせてもよい。添加剤としては、ビニレンカーボネート、シクロヘキシルベンゼン、ジフェニルエーテルなどが用いられる。   In addition, as the non-aqueous electrolyte, a non-aqueous electrolyte solution or a gel electrolyte in which a non-aqueous electrolyte solution is included in a polymer material is used. The non-aqueous electrolyte solution includes a non-aqueous solvent, a solute, and an additive. As the solute, lithium salts such as lithium hexafluorophosphate (LiPF6) and lithium tetrafluoroborate (LiBF4) are used. As the non-aqueous solvent, it is preferable to use cyclic carbonates such as ethylene carbonate and propylene carbonate, and chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, but it is not limited thereto. In addition, a non-aqueous solvent may be used individually by 1 type, but may combine 2 or more types. As the additive, vinylene carbonate, cyclohexylbenzene, diphenyl ether, or the like is used.

以下、本発明の実施の形態1における二次電池の作製方法について説明する。   Hereinafter, a method for manufacturing the secondary battery according to Embodiment 1 of the present invention will be described.

まず、例えば正極活物質としてコバルト酸リチウムを、導電剤として黒鉛および結着剤としてポリフッ化ビニリデン(PVDF)とを用いてそれらを混練して正極合剤を作製し、アルミニウム箔などの正極集電体に塗工する。このとき、正極集電体の幅方向の一端で長手方向に正極合剤未塗工部5aを形成して正極板1を作製する。   First, for example, lithium cobaltate as a positive electrode active material, graphite as a conductive agent and polyvinylidene fluoride (PVDF) as a binder are kneaded to prepare a positive electrode mixture, and a positive electrode current collector such as an aluminum foil Apply to the body. At this time, the positive electrode mixture uncoated portion 5a is formed in the longitudinal direction at one end in the width direction of the positive electrode current collector to produce the positive electrode plate 1.

つぎに、例えば負極活物質として天然黒鉛を、導電剤として黒鉛および結着剤としてスチレン−ブタジエン共重合体ゴム(SBR)とを用いてそれらを混練して負極合剤を作製し、銅箔などの負極集電体に塗工する。このとき、負極集電体の幅方向の一端で長手方向に負極合剤未塗工部6aを形成して負極板2を作製する。   Next, for example, natural graphite is used as the negative electrode active material, graphite is used as the conductive agent, and styrene-butadiene copolymer rubber (SBR) is used as the binder to prepare a negative electrode mixture, and copper foil or the like. The negative electrode current collector is coated. At this time, the negative electrode mixture uncoated portion 6a is formed in the longitudinal direction at one end in the width direction of the negative electrode current collector to produce the negative electrode plate 2.

つぎに、正極板1と負極板2を、例えばポリオレフィンなどの微多孔膜からなるセパレータを介して正極合剤未塗工部5aおよび負極合剤未塗工部6aが互いに反対方向において幅方向に突出させて捲回し、電極群4を形成する。   Next, the positive electrode plate 1 and the negative electrode plate 2 are arranged in the width direction in the opposite direction to each other through the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a through a separator made of a microporous film such as polyolefin. The electrode group 4 is formed by projecting and winding.

つぎに、以下で示す構成からなる折れ曲がり防止部を形成する。つまり、電極群4から互いに反対方向に突出した正極合剤未塗工部5aおよび負極合剤未塗工部6aの捲回軸心の中心部に、例えば樹脂製の内径保持部材7を挿入する。そして、正極合剤未塗工部5aおよび負極合剤未塗工部6aの外周部にリング体8を嵌め込む。さらに、内径保持部材7とリング体8の間の中間部で、少なくとも正極集電部材10および負極集電部材11が配置された下面にばね材9を挿入する。内径保持部材7、リング体8およびばね材9で構成された折れ曲がり防止部により、正極合剤未塗工部5aおよび負極合剤未塗工部6aで示される正極集電体および負極集電体が集合して集電体が補強されるとともに、高さなどが矯正される。   Next, the bending prevention part which consists of a structure shown below is formed. That is, for example, the resin-made inner diameter holding member 7 is inserted into the central portion of the winding shaft center of the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a protruding from the electrode group 4 in opposite directions. . And the ring body 8 is engage | inserted in the outer peripheral part of the positive mix uncoated part 5a and the negative mix uncoated part 6a. Further, the spring material 9 is inserted into at least the lower surface on which the positive electrode current collecting member 10 and the negative electrode current collecting member 11 are arranged at an intermediate portion between the inner diameter holding member 7 and the ring body 8. The positive electrode current collector and the negative electrode current collector shown by the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a by the bending prevention portion constituted by the inner diameter holding member 7, the ring body 8, and the spring material 9. As a result, the current collector is reinforced and the height is corrected.

つぎに、集合した正極合剤未塗工部5aおよび負極合剤未塗工部6aの折れ曲がり防止部で、アルミニウム板などの正極集電部材および銅板などの負極集電部材と、例えばTIG溶接により溶接して電気的に接続する。   Next, in the bending prevention portion of the assembled positive electrode mixture uncoated portion 5a and negative electrode mixture uncoated portion 6a, a positive electrode current collecting member such as an aluminum plate and a negative electrode current collecting member such as a copper plate, for example, by TIG welding Weld and connect electrically.

つぎに、例えば鉄、ニッケルやステンレスなどからなる電池容器12に各集電部材を備えた電極群4を挿入し、電池容器12の底部に負極集電部材を、例えば抵抗溶接により溶接して電気的に接続する。同様に、正極端子を兼ねた封口板14と正極集電部材とを、例えばレーザ溶接により溶接して電気的に接続する。   Next, the electrode group 4 having each current collecting member is inserted into the battery container 12 made of, for example, iron, nickel, stainless steel, etc., and the negative electrode current collecting member is welded to the bottom of the battery container 12 by, for example, resistance welding. Connect. Similarly, the sealing plate 14 that also serves as the positive electrode terminal and the positive electrode current collecting member are electrically connected by welding, for example, by laser welding.

つぎに、エチレンカーボネートなどの非水溶媒と六フッ化リン酸リチウム(LiPF6)などの溶質からなる非水電解質を減圧下で電池容器12内に注入する。   Next, a nonaqueous electrolyte composed of a nonaqueous solvent such as ethylene carbonate and a solute such as lithium hexafluorophosphate (LiPF6) is injected into the battery container 12 under reduced pressure.

つぎに、正極端子を兼ねた封口板14を電池容器12に挿入し、例えば樹脂製のガスケット15を介して封口板14と電池容器12の周縁をかしめて封口することにより、二次電池を作製できる。   Next, a sealing plate 14 that also serves as a positive electrode terminal is inserted into the battery container 12, and the secondary battery is manufactured by, for example, sealing the sealing plate 14 and the battery container 12 by caulking the periphery of the sealing plate 14 with a resin gasket 15. it can.

(実施の形態2)
図4Aは本発明の実施の形態2における折れ曲がり防止部を設けた電極群の状態を説明する断面図で、図4Bは同実施の形態に用いる折れ曲がり防止部を備えた集電部材を示す断面図である。ここで、実施の形態2は実施の形態1と折れ曲がり防止部を集電部材と兼用した点で構成が異なるもので、他の構成は同様である。
(Embodiment 2)
FIG. 4A is a cross-sectional view illustrating a state of an electrode group provided with a bending prevention portion according to Embodiment 2 of the present invention, and FIG. 4B is a cross-sectional view illustrating a current collecting member provided with the bending prevention portion used in the embodiment. It is. Here, the configuration of the second embodiment is different from that of the first embodiment in that the bending prevention portion is also used as a current collecting member, and the other configurations are the same.

すなわち、図4Bに示すように、正極集電部材10および負極集電部材11は、電極群4の端面の位置に設置され、電極群4の露出部に嵌め込まれる電極群4の外周部および内周部の位置にリブ16を備えている。このとき、リブ16が折れ曲がり防止部として機能するものである。そして、リブ16を電極群4の集電体の露出部の位置で嵌め合わせ、電極群4の正極合剤未塗工部5aと正極集電部材10および負極合剤未塗工部6aと負極集電部材11とを、例えばTIG溶接により溶接して電気的に接続する。つまり、正極集電体の露出部および負極集電体の露出部を、リブ16により位置決めできるため折れ曲がりを防止できる。なお、正極集電部材10および負極集電部材11のリブ16は、電極群4の捲回方向の円周に沿って形成されていても、放射状に形成されていてもよい。上記により、実施の形態1と同様に二次電池を作製できる。   That is, as shown in FIG. 4B, the positive electrode current collecting member 10 and the negative electrode current collecting member 11 are installed at the position of the end face of the electrode group 4, and the outer peripheral part and the inner part of the electrode group 4 fitted into the exposed part of the electrode group 4. Ribs 16 are provided at the circumferential positions. At this time, the rib 16 functions as a bending prevention part. And the rib 16 is fitted in the position of the exposed part of the collector of the electrode group 4, and the positive electrode mixture uncoated part 5a of the electrode group 4, the positive electrode current collecting member 10, the negative electrode mixture uncoated part 6a, and the negative electrode The current collecting member 11 is electrically connected by welding, for example, by TIG welding. In other words, since the exposed portion of the positive electrode current collector and the exposed portion of the negative electrode current collector can be positioned by the rib 16, bending can be prevented. The ribs 16 of the positive electrode current collector 10 and the negative electrode current collector 11 may be formed along the circumference of the electrode group 4 in the winding direction or may be formed radially. As described above, a secondary battery can be manufactured as in the first embodiment.

なお、リブ16の高さは、正極合剤未塗工部5aおよび負極合剤未塗工部6aと正極集電部材10および負極集電部材11との均一な接続を実現するために、正極合剤未塗工部5aおよび負極合剤未塗工部6aの幅よりも小さくすることが重要である。すなわち、リブ16により電極群4の高さを規制し、均一な形状の電極群4を得ることができる。   The height of the rib 16 is set so that the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a are connected to the positive electrode current collecting member 10 and the negative electrode current collecting member 11 in a uniform manner. It is important to make the width smaller than the width of the unmixed portion 5a and the negative electrode uncoated portion 6a. That is, the height of the electrode group 4 is regulated by the ribs 16, and the electrode group 4 having a uniform shape can be obtained.

また、図4Aでは、電極群4の内周部および外周部に嵌め合わされる位置にリブ16を形成した例で説明したが、これに限られず、集電体の露出部の折れ曲がりを防止できる位置であれば任意の位置にリブ16を設けてもよい。   Moreover, although FIG. 4A demonstrated the example which formed the rib 16 in the position fitted to the inner peripheral part and outer peripheral part of the electrode group 4, it is not restricted to this, The position which can prevent the bending of the exposed part of an electrical power collector If so, the rib 16 may be provided at an arbitrary position.

また、実施の形態2の場合には、内径保持部材を設けても設けなくてもよい。   In the case of the second embodiment, the inner diameter holding member may or may not be provided.

本発明の実施の形態2によれば、正極合剤未塗工部5aで示す正極集電体および負極合剤未塗工部6aで示す負極集電体と、正極集電部材10および負極集電部材11との接続時に生じる折れ曲がりをリブ16により防止して、均一な接続が得られる。また、リブ16により電極群4の高さを規制することができるため、均一な形状の電極群4による電池特性の安定した二次電池を生産性よく実現できる。   According to Embodiment 2 of the present invention, the positive electrode current collector indicated by the positive electrode mixture uncoated portion 5a and the negative electrode current collector indicated by the negative electrode mixture uncoated portion 6a, the positive electrode current collecting member 10, and the negative electrode current collector The bending which occurs at the time of connection with the electric member 11 is prevented by the rib 16, and a uniform connection is obtained. In addition, since the height of the electrode group 4 can be regulated by the rib 16, a secondary battery having stable battery characteristics by the electrode group 4 having a uniform shape can be realized with high productivity.

(実施の形態3)
図5Aは本発明の実施の形態3における二次電池の電極群の構成を説明する斜視図で、図5Bは図5Aの部分拡大斜視図である。ここで、実施の形態3は実施の形態1と折れ曲がり防止部の構成が異なるもので、他の構成は同様である。
(Embodiment 3)
FIG. 5A is a perspective view illustrating the configuration of the electrode group of the secondary battery according to Embodiment 3 of the present invention, and FIG. 5B is a partially enlarged perspective view of FIG. 5A. Here, the third embodiment is different from the first embodiment in the configuration of the bending prevention unit, and the other configurations are the same.

つまり、図5Aに示すように、電極群4において突出した正極合剤未塗工部(図示せず)および負極合剤未塗工部(図示せず)の外周に、例えば樹脂製の収縮リング体17を装着する。そして、収縮リング体17を加熱して収縮させて、図4Aに示す正極合剤未塗工部5aおよび負極合剤未塗工部6aを集合させて折れ曲がり防止部とするものである。   That is, as shown in FIG. 5A, for example, a resin-made shrink ring is formed on the outer periphery of the positive electrode mixture uncoated part (not shown) and the negative electrode mixture uncoated part (not shown) protruding in the electrode group 4. Wear body 17. And the shrink ring body 17 is heated and contracted, and the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a shown in FIG. 4A are assembled to form a bending prevention portion.

ここで、収縮リング体17としては、特に限定されないが、例えばフッ素樹脂、PFA、FEP、ポリオレフィンやポリ塩化ビニルなどを用いることができる。   Here, the shrink ring body 17 is not particularly limited. For example, fluororesin, PFA, FEP, polyolefin, polyvinyl chloride, or the like can be used.

なお、この場合、内径保持部材7としては、加熱により収縮しないものが好ましく、反対に膨張する材料であればさらに好ましい。   In this case, the inner diameter holding member 7 is preferably a material that does not shrink by heating, and more preferably a material that expands on the contrary.

本発明の実施の形態3によれば、正極合剤未塗工部で示す正極集電体および負極合剤未塗工部で示す負極集電体を収縮リング体17の収縮により集合させて機械的な強度を向上させる。この結果、正極集電部材および負極集電部材との接続時に生じる折れ曲がりが防止され、均一な接続を実現できる。また、収縮リング体17により電極群4の高さを規制することができるため、均一な形状の電極群による電池特性の安定した二次電池を生産性よく実現できる。   According to the third embodiment of the present invention, the positive electrode current collector indicated by the positive electrode mixture uncoated part and the negative electrode current collector indicated by the negative electrode mixture uncoated part are assembled by contraction of the contraction ring body 17. To improve the strength. As a result, bending that occurs at the time of connection between the positive electrode current collecting member and the negative electrode current collecting member is prevented, and a uniform connection can be realized. In addition, since the height of the electrode group 4 can be regulated by the contraction ring body 17, a secondary battery having stable battery characteristics by the electrode group having a uniform shape can be realized with high productivity.

(実施の形態4)
図6Aは本発明の実施の形態4における二次電池の電極群4の構成を説明する斜視図で、図6Bは図6Aの部分拡大斜視図である。ここで、実施の形態4は実施の形態1と折れ曲がり防止部の構成が異なるもので、他の構成は同様である。
(Embodiment 4)
6A is a perspective view illustrating the configuration of electrode group 4 of the secondary battery according to Embodiment 4 of the present invention, and FIG. 6B is a partially enlarged perspective view of FIG. 6A. Here, the fourth embodiment is different from the first embodiment in the configuration of the bending preventing portion, and the other configurations are the same.

つまり、図6Aに示すように、電極群4において突出した正極合剤未塗工部5aおよび負極合剤未塗工部6aの外周に、例えば樹脂製の締結バンドなどからなる締結部材18を装着する。そして、締結部材18を締結することにより、正極合剤未塗工部5aおよび負極合剤未塗工部6aを集合させて折れ曲がり防止部とするものである。   That is, as shown in FIG. 6A, a fastening member 18 made of, for example, a resin fastening band is attached to the outer periphery of the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a protruding from the electrode group 4. To do. Then, by fastening the fastening member 18, the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a are gathered to form a bending prevention portion.

なお、締結部材18として、締結バンドの他に、糸や紐などを帯状に巻きつけてもよい。   In addition to the fastening band, a thread or string may be wound around the fastening member 18 in a band shape.

本発明の実施の形態4によれば、正極合剤未塗工部で示す正極集電体および負極合剤未塗工部で示す負極集電体を、締結部材18の締め付けにより集合させて機械的な強度を向上させる。この結果、正極集電部材および負極集電部材との接続時に生じる折れ曲がりが防止され、均一な接続を実現する。また、締結部材18と内径保持部材7により電極群4の高さを規制できるため、均一な形状の電極群4による電池特性の安定した二次電池を生産性よく実現できる。   According to the fourth embodiment of the present invention, the positive electrode current collector indicated by the positive electrode mixture uncoated portion and the negative electrode current collector indicated by the negative electrode mixture uncoated portion are assembled together by fastening the fastening member 18 to the machine. To improve the strength. As a result, bending that occurs at the time of connection between the positive current collecting member and the negative current collecting member is prevented, and a uniform connection is realized. In addition, since the height of the electrode group 4 can be regulated by the fastening member 18 and the inner diameter holding member 7, a secondary battery having stable battery characteristics by the electrode group 4 having a uniform shape can be realized with high productivity.

(実施の形態5)
図7Aは本発明の実施の形態5における二次電池の電極群の構成を説明する斜視図で、図7Bは図7Aの部分拡大斜視図である。ここで、実施の形態5は実施の形態1と折れ曲がり防止部の構成が異なるもので、他の構成は同様である。
(Embodiment 5)
7A is a perspective view illustrating the configuration of the electrode group of the secondary battery according to Embodiment 5 of the present invention, and FIG. 7B is a partially enlarged perspective view of FIG. 7A. Here, the fifth embodiment is different from the first embodiment in the configuration of the bending prevention unit, and the other configurations are the same.

つまり、図7Aに示すように、電極群4において突出した正極合剤未塗工部(図示せず)および負極合剤未塗工部(図示せず)の外周に、例えば樹脂製のプッシュナット状リング体19を装着する。そして、プッシュナット状リング体19の内周に設けた突出部20により、図4Aに示す正極合剤未塗工部5aおよび負極合剤未塗工部6aを集合させて折れ曲がり防止部とするものである。   That is, as shown in FIG. 7A, for example, a resin-made push nut is provided on the outer periphery of the positive electrode mixture uncoated portion (not shown) and the negative electrode mixture uncoated portion (not shown) protruding in the electrode group 4. A ring-shaped body 19 is attached. Then, the positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a shown in FIG. 4A are assembled by the protruding portion 20 provided on the inner periphery of the push nut-shaped ring body 19 to form a bending prevention portion. It is.

本発明の実施の形態5によれば、正極合剤未塗工部で示す正極集電体および負極合剤未塗工部で示す負極集電体を、プッシュナット状リング体19の内周の突出部20により集合させて機械的な強度を向上させる。この結果、正極集電部材および負極集電部材との接続時に生じる折れ曲がりが防止され、均一な接続を実現できる。また、プッシュナット状リング体19と内径保持部材7により電極群4の折れ曲がりによる高さのばらつきを矯正できるため、均一な形状の電極群による電池特性の安定した二次電池を生産性よく実現できる。   According to the fifth embodiment of the present invention, the positive electrode current collector indicated by the positive electrode mixture uncoated portion and the negative electrode current collector indicated by the negative electrode mixture uncoated portion are arranged on the inner periphery of the push nut-shaped ring body 19. Aggregated by the protrusions 20 improves the mechanical strength. As a result, bending that occurs at the time of connection between the positive electrode current collecting member and the negative electrode current collecting member is prevented, and a uniform connection can be realized. Further, since the push nut-like ring body 19 and the inner diameter holding member 7 can correct the height variation due to the bending of the electrode group 4, a secondary battery having a uniform battery characteristic and a stable battery characteristic can be realized with high productivity. .

(実施の形態6)
図8Aは本発明の実施の形態6における二次電池の正極板の展開図で、図8Bは負極板の展開図である。図9は、同実施の形態における二次電池の構成を示す断面図である。ここで、実施の形態6は実施の形態1と正極板および負極板の構成が異なるもので、他の構成は同様である。
(Embodiment 6)
8A is a development view of the positive electrode plate of the secondary battery according to Embodiment 6 of the present invention, and FIG. 8B is a development view of the negative electrode plate. FIG. 9 is a cross-sectional view showing the configuration of the secondary battery in the same embodiment. Here, the sixth embodiment is different from the first embodiment in the configuration of the positive electrode plate and the negative electrode plate, and the other configurations are the same.

つまり、図8Aに示すように、正極板1のうち正極合剤塗工部5bと正極合剤未塗工部5aとの間の少なくとも境界近傍に補強層21が設けられている。同様に、図8Bに示すように、負極板2のうち負極合剤塗工部6bと負極合剤未塗工部6aとの間の少なくとも境界近傍に補強層21が設けられている。   That is, as shown in FIG. 8A, the reinforcing layer 21 is provided at least near the boundary between the positive electrode mixture coated portion 5b and the positive electrode mixture uncoated portion 5a in the positive electrode plate 1. Similarly, as shown in FIG. 8B, a reinforcing layer 21 is provided at least near the boundary between the negative electrode mixture coated portion 6b and the negative electrode mixture uncoated portion 6a in the negative electrode plate 2.

ここで、補強層21の作成方法を説明する。まず、例えばアルミナなどの無機酸化物フィラーと結着剤と適量のN−メチル−2−ピロリドン(N−Methyl−2−Pyrrolidone、以下では「NMP」と記す)とを混練してスラリーを作製する。そして、そのスラリーを正極合剤塗工部5bと正極合剤未塗工部5aとの境界および負極合剤塗工部6bと負極合剤未塗工部6aとの境界に塗布して乾燥させ、補強層21を形成する。このとき、補強層21の厚みは、正極合剤塗工部5bおよび負極合剤塗工部6bの厚み以下で形成することが好ましい。   Here, a method of creating the reinforcing layer 21 will be described. First, for example, an inorganic oxide filler such as alumina, a binder, and an appropriate amount of N-methyl-2-pyrrolidone (N-Methyl-2-Pyrrolidone, hereinafter referred to as “NMP”) are kneaded to prepare a slurry. . Then, the slurry is applied to the boundary between the positive electrode mixture coated portion 5b and the positive electrode mixture uncoated portion 5a and the boundary between the negative electrode mixture coated portion 6b and the negative electrode mixture uncoated portion 6a and dried. The reinforcing layer 21 is formed. At this time, the reinforcing layer 21 is preferably formed to have a thickness equal to or less than the thickness of the positive electrode mixture coating portion 5b and the negative electrode mixture coating portion 6b.

本実施の形態6によれば、補強層21を設けることにより、集電体の露出部の機械的強度の低下を抑制できる。また、接合時における各正極合剤未塗工部5a、負極合剤未塗工部6aの折れ曲がりを防止できるため、二次電池の製造歩留まりをさらに向上させることができる。   According to the sixth embodiment, by providing the reinforcing layer 21, it is possible to suppress a decrease in the mechanical strength of the exposed portion of the current collector. Moreover, since the bending of each positive electrode mixture uncoated portion 5a and the negative electrode mixture uncoated portion 6a at the time of joining can be prevented, the production yield of the secondary battery can be further improved.

以下に、本発明の各実施の形態における具体的な実施例について説明する。   Specific examples in each embodiment of the present invention will be described below.

(実施例1)
実施例1は、上記実施の形態1を具体化した一例である。
Example 1
Example 1 is an example in which Embodiment 1 is embodied.

はじめに、リチウムイオンを吸蔵・放出可能な正極板を、以下の方法で作製した。   First, a positive electrode plate capable of inserting and extracting lithium ions was produced by the following method.

まず、正極合剤として、コバルト酸リチウム粉末を85重量部、導電剤として炭素粉末を10重量部、および結着剤としてポリフッ化ビニリデン(以下、「PVDF」と記す)のNMP溶液(PVDFが5重量部相当)を混合する。   First, 85 parts by weight of lithium cobaltate powder as a positive electrode mixture, 10 parts by weight of carbon powder as a conductive agent, and an NMP solution of polyvinylidene fluoride (hereinafter referred to as “PVDF”) as a binder (PVDF is 5 parts by weight). Part by weight).

つぎに、得られた混合物を厚み15μmで幅56mmのアルミニウム箔の正極集電体の両面にドクターブレード法を用いて幅50mmの正極合剤塗工部に塗布し、乾燥した後、圧延して厚みが150μmで、幅6mmの正極合剤未塗工部を設けた正極板を作製した。   Next, the obtained mixture was applied to both sides of a positive electrode current collector of aluminum foil having a thickness of 15 μm and a width of 56 mm using a doctor blade method on a positive electrode mixture coating portion having a width of 50 mm, dried, and then rolled. A positive electrode plate having a thickness of 150 μm and a positive electrode mixture uncoated portion having a width of 6 mm was produced.

さらに、リチウムイオンを吸蔵・放出可能な負極板を、以下の方法で作製した。   Furthermore, a negative electrode plate capable of inserting and extracting lithium ions was produced by the following method.

まず、負極合剤として、人造黒鉛粉末を95重量部、および結着剤としてPVDFのNMP溶液(PVDFが5重量部相当)を混合した。   First, 95 parts by weight of artificial graphite powder was mixed as a negative electrode mixture, and an NMP solution of PVDF (PVDF was equivalent to 5 parts by weight) was mixed as a binder.

つぎに、得られた混合物を厚み10μm、幅57mmの銅箔の負極集電体の両面にドクターブレード法を用いて幅52mmの負極合剤塗工部に塗布し、乾燥した後、負極合剤塗工部を圧延して厚みが140μmで、幅5mmの負極合剤未塗工部を設けた負極板を作製した。   Next, the obtained mixture was applied to both sides of a negative electrode current collector of copper foil having a thickness of 10 μm and a width of 57 mm using a doctor blade method on a negative electrode mixture coating portion having a width of 52 mm, and dried, and then the negative electrode mixture The coated part was rolled to produce a negative electrode plate having a thickness of 140 μm and a negative electrode mixture uncoated part having a width of 5 mm.

上記のようにして作製した正極板と負極板を、厚み25μmのポリプロピレン樹脂製微多孔フィルムよりなるセパレータを配して渦巻き状に捲回し、円筒状の電極群を作製する。   The positive electrode plate and the negative electrode plate manufactured as described above are spirally wound with a separator made of a polypropylene resin microporous film having a thickness of 25 μm, and a cylindrical electrode group is manufactured.

そして、捲回された電極群の両端から突出した正極合剤未塗工部の正極集電体と負極合剤未塗工部の負極集電体の捲回軸心φ5mmの中心部に内径保持部材として、外径4.8mm、内径4.4mm、高さ3mmの筒を、外周に外径25.5mm、内径24mm、高さ3mmのリング体を装着した。また、電極群の内周と外周との中間部で、少なくとも正極集電部材および負極集電部材と接続する位置に厚み0.2mm、高さが3mmの楔状のばね材を装着した。さらに、上記で得られた電極群に装着したばね材の位置で外径25.5mm、厚み0.5mmの円盤状のアルミニウム板からなる正極集電部材をTIG溶接し、外径25.5mm、厚み0.3mmの円盤状の銅板からなる負極集電部材をTIG溶接した。このとき、TIG溶接の溶接条件としては、正極では電流値を100A、時間を100msec、負極では電流値を130A、時間を50msecで行った。   The inner diameter is maintained at the center of the winding axis φ5 mm of the positive electrode current collector of the positive electrode mixture uncoated portion and the negative electrode current collector of the negative electrode mixture uncoated portion protruding from both ends of the wound electrode group As a member, a cylinder having an outer diameter of 4.8 mm, an inner diameter of 4.4 mm, and a height of 3 mm was attached to a ring body having an outer diameter of 25.5 mm, an inner diameter of 24 mm, and a height of 3 mm. In addition, a wedge-shaped spring material having a thickness of 0.2 mm and a height of 3 mm was attached at least at a position where the positive electrode current collector and the negative electrode current collector were connected at an intermediate portion between the inner periphery and the outer periphery of the electrode group. Furthermore, TIG welding was performed on the positive electrode current collector member made of a disc-shaped aluminum plate having an outer diameter of 25.5 mm and a thickness of 0.5 mm at the position of the spring material attached to the electrode group obtained above, and the outer diameter was 25.5 mm. A negative electrode current collector made of a disc-shaped copper plate having a thickness of 0.3 mm was TIG welded. At this time, as the welding conditions for TIG welding, the current value was 100 A for the positive electrode, the time was 100 msec, the current value was 130 A for the negative electrode, and the time was 50 msec.

そして、得られた電極群を片側のみ開口した円筒型の電池容器(材質:鉄/Niめっき、直径26mm、高さ65mm)に挿入し、電池容器と電極群との間に絶縁板を配置して負極集電部材と電池容器とを抵抗溶接した後、正極集電部材と封口板とをレーザ溶接して電池容器を作製した。   The obtained electrode group is inserted into a cylindrical battery container (material: iron / Ni plating, diameter 26 mm, height 65 mm) opened on only one side, and an insulating plate is disposed between the battery container and the electrode group. The negative electrode current collector and the battery container were resistance welded, and then the positive electrode current collector and the sealing plate were laser welded to produce a battery container.

つぎに、非水溶媒として、エチレンカーボネートとエチルメチルカーボネートを体積比1:1で混合し、これに溶質として、六フッ化リン酸リチウム(LiPF6)が1mol/Lになるように溶解させて調製し非水電解質を作製した。   Next, ethylene carbonate and ethyl methyl carbonate are mixed at a volume ratio of 1: 1 as a non-aqueous solvent, and dissolved therein so that lithium hexafluorophosphate (LiPF6) is 1 mol / L as a solute. A non-aqueous electrolyte was produced.

つぎに、得られた電池容器を真空中で60℃に加熱して乾燥した後、調整した非水電解質を注入した。   Next, after heating the obtained battery container at 60 degreeC in vacuum and drying, the adjusted nonaqueous electrolyte was inject | poured.

そして、封口板をガスケットを介して電池容器でかしめて封止し、直径26mm、高さ65mmで設計容量2600mAhの円筒型の二次電池を作製した。これを、サンプル1とする。   Then, the sealing plate was squeezed and sealed with a battery container through a gasket to produce a cylindrical secondary battery having a diameter of 26 mm, a height of 65 mm, and a design capacity of 2600 mAh. This is sample 1.

(実施例2)
実施例2は、上記実施の形態2を具体化した一例である。
(Example 2)
Example 2 is an example in which Embodiment 2 is embodied.

まず、外径25.5mm、厚み0.5mm、中心部に直径5mmの貫通孔を設けた円盤状のアルミニウム板からなる正極集電部材と、外径25.5mm、厚み0.3mm、中心部に直径5mmの貫通孔を設けた円盤状の銅板からなる負極集電部材の外周部と内周部に、高さ1mmのリブを電極群の捲回方向の円周に沿って設けた。   First, a positive electrode current collector made of a disc-shaped aluminum plate having an outer diameter of 25.5 mm, a thickness of 0.5 mm, and a through hole having a diameter of 5 mm in the center, an outer diameter of 25.5 mm, a thickness of 0.3 mm, and a center Ribs having a height of 1 mm were provided along the circumference in the winding direction of the electrode group on the outer peripheral portion and the inner peripheral portion of the negative electrode current collector made of a disk-shaped copper plate provided with a through-hole having a diameter of 5 mm.

そして、実施例1と同様の方法で作製した電極群の両端で、電極群の外周部と内周部に、正極集電部材と負極集電体のリブを介して嵌め込み、正極集電部材と正極合剤未塗工部および負極集電部材と負極合剤未塗工部を、TIG溶接した以外は実施例1と同様にして二次電池を作製した。これを、サンプル2とする。   Then, at both ends of the electrode group produced in the same manner as in Example 1, the positive electrode current collector member and the positive electrode current collector member were fitted into the outer peripheral part and the inner peripheral part of the electrode group via the ribs of the positive electrode current collector and the negative electrode current collector. A secondary battery was produced in the same manner as in Example 1 except that the positive electrode mixture uncoated part, the negative electrode current collector and the negative electrode mixture uncoated part were TIG welded. This is Sample 2.

(実施例3)
実施例3は、上記実施の形態3を具体化した一例である。
(Example 3)
Example 3 is an example in which the third embodiment is embodied.

実施例1と同様の方法で作製した電極群の両端に正極合剤未塗工部および負極合剤未塗工部の外周にポリオレフィンからなる外径25.5mm、厚み0.1mmの収縮リング体を装着し、150℃で加熱して折れ曲がり防止部を形成した以外は実施例1と同様の方法で二次電池を作製した。これを、サンプル3とする。   A shrink ring body having an outer diameter of 25.5 mm and a thickness of 0.1 mm made of polyolefin on the outer periphery of the positive electrode mixture uncoated part and the negative electrode mixture uncoated part at both ends of the electrode group produced by the same method as in Example 1. A secondary battery was fabricated in the same manner as in Example 1 except that the bending prevention portion was formed by heating at 150 ° C. This is designated as Sample 3.

(実施例4)
実施例4は、上記実施の形態4を具体化した一例である。
(Example 4)
Example 4 is an example in which Embodiment 4 is embodied.

実施例1と同様の方法で作製した電極群の両端に正極合剤未塗工部および負極合剤未塗工部の外周にポリプロピレンからなる幅3mm、長さ80mmの締結部材を装着し、締結して折れ曲がり防止部を形成した以外は実施例1と同様の方法で二次電池を作製した。これを、サンプル4とする。   A fastening member having a width of 3 mm and a length of 80 mm made of polypropylene is attached to the outer periphery of the positive electrode mixture uncoated portion and the negative electrode mixture uncoated portion on both ends of the electrode group produced in the same manner as in Example 1, and fastened. Then, a secondary battery was fabricated in the same manner as in Example 1 except that the bending prevention portion was formed. This is designated as sample 4.

(実施例5)
実施例5は、上記実施の形態5を具体化した一例である。
(Example 5)
Example 5 is an example in which Embodiment 5 is embodied.

実施例1と同様の方法で作製した電極群の両端に正極合剤未塗工部および負極合剤未塗工部の外周にポリプロピレンからなる外径25.5mmのプッシュナット状リング体を装着し、内周の突出部で折れ曲がり防止部を形成した以外は実施例1と同様の方法で二次電池を作製した。これを、サンプル5とする。   A push nut-like ring body having an outer diameter of 25.5 mm made of polypropylene is attached to the outer periphery of the positive electrode mixture uncoated part and the negative electrode mixture uncoated part on both ends of the electrode group produced in the same manner as in Example 1. A secondary battery was fabricated in the same manner as in Example 1 except that the bending prevention portion was formed at the protruding portion on the inner periphery. This is designated as Sample 5.

(実施例6)
実施例6は、上記実施の形態6を具体化した一例である。
(Example 6)
Example 6 is an example in which the sixth embodiment is embodied.

まず、無機酸化物フィラーであるアルミナとポリアクリロニトリル変性ゴム結着剤とNMP溶液とを混練し、補強層用のスラリーを作製した。   First, alumina, which is an inorganic oxide filler, a polyacrylonitrile-modified rubber binder, and an NMP solution were kneaded to prepare a slurry for a reinforcing layer.

つぎに、正極合剤塗工部に接する正極合剤未塗工部の一部分に、補強層用のスラリーを幅4mm、片面側当り厚み67.5μmで塗布した後、そのスラリーを乾燥させて補強層を形成した。このとき、補強層の厚みは、正極合剤塗工部の厚みとほぼ同じであった。同様の方法で、負極板にも、幅4mm、片面側当り厚み62μmの補強層を形成した。   Next, a slurry for reinforcing layer is applied in a width of 4 mm and a thickness per side of 67.5 μm on a part of the positive electrode mixture uncoated portion in contact with the positive electrode mixture coated portion, and then the slurry is dried to be reinforced. A layer was formed. At this time, the thickness of the reinforcing layer was substantially the same as the thickness of the positive electrode mixture coating portion. In the same manner, a reinforcing layer having a width of 4 mm and a thickness per side of 62 μm was also formed on the negative electrode plate.

また、以上の方法で作製した正極板および負極板を用いて実施例1と同様の方法で二次電池を作製した。これを、サンプル6とする。   Moreover, the secondary battery was produced by the method similar to Example 1 using the positive electrode plate and negative electrode plate which were produced by the above method. This is designated as Sample 6.

(比較例1)
比較例1は、特許文献2を具体化した一例である。すなわち、捲回した正極合剤未塗工部および負極合剤未塗工部を幅方向に沿って折り畳んで正極集電体および負極集電体を形成した以外は実施例1と同様の方法で二次電池を作製した。これを、サンプルC1とする。
(Comparative Example 1)
Comparative Example 1 is an example in which Patent Document 2 is embodied. That is, in the same manner as in Example 1 except that the wound positive electrode mixture uncoated part and negative electrode mixture uncoated part were folded along the width direction to form the positive electrode current collector and the negative electrode current collector. A secondary battery was produced. This is designated as sample C1.

以上のように作製した各サンプルの二次電池、各50個を用いて、以下に示す評価を行った。そして、サンプル1〜サンプル6とサンプルC1の評価結果を(表1)に示す。   The evaluation shown below was performed using 50 secondary batteries of each sample produced as described above. The evaluation results of Sample 1 to Sample 6 and Sample C1 are shown in (Table 1).

Figure 0004835594
Figure 0004835594

まず、作製した二次電池の電池容器から電極群を取り出して、極板の折れ曲がり状態を視認により観察した。測定結果を(表1)の「極板の状態」の欄に示す。   First, the electrode group was taken out from the battery container of the produced secondary battery, and the bent state of the electrode plate was visually observed. The measurement results are shown in the column “State of electrode plate” in (Table 1).

(表1)に示すように、サンプル1〜サンプル6のいずれの二次電池も合剤部に歪が生じるほどの折れ曲がりはほとんど観察されなかった。このとき、極板に若干曲がっている部分が観察されたが、この曲がりは溶接時に集電部材を電極群の端面に当接させたことに起因するものと考えられる。そのため、サンプル6には補強層が設けられているので、極板の折れ曲がりは皆無であった。一方、サンプルC1では、合剤塗工部と未塗工部の境界で折れ曲がりが発生し、合剤の剥離や破損などが多数観察された。   As shown in (Table 1), almost all of the secondary batteries of Sample 1 to Sample 6 were not observed to be bent so as to cause distortion in the mixture portion. At this time, a slightly bent portion of the electrode plate was observed, but this bending is considered to be caused by bringing the current collecting member into contact with the end face of the electrode group during welding. Therefore, since the reinforcing layer was provided in the sample 6, there was no bending of the electrode plate. On the other hand, in sample C1, bending occurred at the boundary between the mixture-coated portion and the uncoated portion, and many peeling and breakage of the mixture were observed.

また、各サンプルから5個ずつ抜き取って、JIS Z2241に基づいて溶接部における引張強度を測定した。具体的には、引張試験機の一方に電極群を保持し、引張試験機の他方に集電部材を保持する。この状態で、一定の速度で引張試験機の軸方向に電極群と集電部材とを引っ張る。そして、溶接部が破壊したときの荷重を、引張強度とした。測定結果を(表1)の「引張強度」の欄に示す。   In addition, five samples were extracted from each sample, and the tensile strength at the weld was measured based on JIS Z2241. Specifically, the electrode group is held on one side of the tensile tester, and the current collecting member is held on the other side of the tensile tester. In this state, the electrode group and the current collecting member are pulled in the axial direction of the tensile tester at a constant speed. And the load when a welding part destroyed was made into tensile strength. The measurement results are shown in the column of “Tensile strength” in (Table 1).

(表1)に示すように、サンプル1〜サンプル6のいずれにおいても、引張強度は50N以上であった。一方、サンプルC1は、5個のうち3個の引張強度は10N以下であり、その溶接部が外れていた。   As shown in (Table 1), in any of Sample 1 to Sample 6, the tensile strength was 50 N or more. On the other hand, in sample C1, three of the five pieces had a tensile strength of 10 N or less, and the welded portion was detached.

さらに、サンプル1〜サンプル6とサンプルC1に対して、内部抵抗を測定した。具体的には、まず、各サンプルに対して、1250mAの定電流で4.2Vまで充電した後、1250mAの定電流で3.0Vまで放電する充放電サイクルを3回繰り返した。そして、1kHzの交流を各サンプルに印加して二次電池の内部抵抗を測定し、接続状態を評価した。測定結果を(表1)の「内部抵抗」の欄に示す。   Furthermore, internal resistance was measured with respect to Sample 1 to Sample 6 and Sample C1. Specifically, first, after charging to 4.2 V with a constant current of 1250 mA for each sample, a charge / discharge cycle of discharging to 3.0 V with a constant current of 1250 mA was repeated three times. And the alternating current of 1 kHz was applied to each sample, the internal resistance of the secondary battery was measured, and the connection state was evaluated. The measurement results are shown in the column of “Internal resistance” in (Table 1).

(表1)に示すように、サンプル1とサンプル2においては、内部抵抗の平均値は5mΩであり、そのばらつきは10%程度であった。また、サンプル3〜サンプル6においては、内部抵抗の平均値は5.8mΩであり、そのばらつきは5%程度であった。   As shown in Table 1, in Sample 1 and Sample 2, the average value of the internal resistance was 5 mΩ, and the variation was about 10%. In samples 3 to 6, the average value of the internal resistance was 5.8 mΩ, and the variation was about 5%.

一方、サンプルC1においては、内部抵抗の平均値は11mΩであり、そのばらつきは20%であった。   On the other hand, in sample C1, the average value of the internal resistance was 11 mΩ, and the variation was 20%.

また、各サンプルの内部抵抗測定値(R)から平均出力電流(I)を計算した。具体的には、電池を4.2Vまで充電した後、1.5Vまで放電した場合には、I=(4.2−1.5)/Rから計算される。その結果を(表1)の「出力電流」の欄に示す。   Further, the average output current (I) was calculated from the measured internal resistance value (R) of each sample. Specifically, when the battery is charged to 4.2V and then discharged to 1.5V, it is calculated from I = (4.2-1.5) / R. The results are shown in the “Output Current” column of (Table 1).

(表1)に示すように、サンプル1〜サンプル6を用いれば、大電流放電を行うことが可能であることがわかった。   As shown in (Table 1), it was found that if Sample 1 to Sample 6 were used, large current discharge could be performed.

なお、各実施例の二次電池では、電極群の捲回軸心の中心部に内径保持部材を挿入した例で説明したが、内径保持部材を除いても特に問題はなく同様の効果が得られた。   In the secondary battery of each example, the example in which the inner diameter holding member is inserted at the center of the winding axis of the electrode group has been described. However, there is no particular problem even if the inner diameter holding member is omitted, and the same effect is obtained. It was.

しかし、上記各実施例で説明した折れ曲がり防止部として内径保持部材のみで構成した二次電池においては、本発明の効果は得られず、集電体の折れ曲がりや合剤塗工部での剥離が発生していた。   However, in the secondary battery composed only of the inner diameter holding member as the bending prevention portion described in each of the above embodiments, the effect of the present invention cannot be obtained, and the current collector is bent or peeled off at the mixture coating portion. It has occurred.

以上、上記実施例では、円筒型の電池について述べたが、これに限られない。例えば、角型の電池やニッケル水素蓄電池およびニッケルカドミウム蓄電池などの二次電池についても本発明の効果を同様に得ることができる。   As described above, the cylindrical battery has been described in the above embodiment, but the present invention is not limited to this. For example, the effects of the present invention can be similarly obtained for secondary batteries such as prismatic batteries, nickel metal hydride storage batteries, and nickel cadmium storage batteries.

本発明は、折れ曲がり防止部により、各集電部材と各合剤未塗工部で示す各集電体とを均一で信頼性よく接続するとともに、各集電体から各合剤の剥離を未然に防ぐことができる。それにより、低抵抗の接続により大電流での充放電を実現し、今後、大きな需要が期待される高出力を必要とする電動工具や電気自動車などの駆動用電池として有用である。   The present invention provides a uniform and reliable connection between each current collecting member and each current collector indicated by each material uncoated portion by means of a bend preventing portion, and also prevents each material from being separated from each current collector. Can be prevented. As a result, charging / discharging with a large current is realized by a low-resistance connection, and it is useful as a battery for driving electric tools, electric vehicles, and the like that require high output, which is expected to be in great demand in the future.

本発明の実施の形態1における二次電池の概略断面図Schematic cross-sectional view of the secondary battery in Embodiment 1 of the present invention 図1AのB部拡大図Part B enlarged view of FIG. 1A 図1AのC部拡大図Part C enlarged view of FIG. 1A 同実施の形態で用いる正極板の展開図Development view of positive electrode plate used in the same embodiment 同実施の形態で用いる負極板の展開図Development view of negative electrode plate used in the same embodiment 同実施の形態で用いるばね材の一例を示す斜視図The perspective view which shows an example of the spring material used in the embodiment 同実施の形態で用いるばね材の一例を示す斜視図The perspective view which shows an example of the spring material used in the embodiment 本発明の実施の形態2における折れ曲がり防止部を設けた電極群の状態を説明する断面図Sectional drawing explaining the state of the electrode group which provided the bending prevention part in Embodiment 2 of this invention 同実施の形態に用いる折れ曲がり防止部を備えた集電部材を示す断面図Sectional drawing which shows the current collection member provided with the bending prevention part used for the embodiment 本発明の実施の形態3における二次電池の電極群の構成を説明する斜視図The perspective view explaining the structure of the electrode group of the secondary battery in Embodiment 3 of this invention. 図5Aの部分拡大斜視図Partial enlarged perspective view of FIG. 5A 本発明の実施の形態4における二次電池の電極群の構成を説明する斜視図The perspective view explaining the structure of the electrode group of the secondary battery in Embodiment 4 of this invention. 図6Aの部分拡大斜視図Partial enlarged perspective view of FIG. 6A 本発明の実施の形態5における二次電池の電極群の構成を説明する斜視図The perspective view explaining the structure of the electrode group of the secondary battery in Embodiment 5 of this invention. 図7Aの部分拡大斜視図Partial enlarged perspective view of FIG. 7A 本発明の実施の形態6における二次電池の正極板の展開図Exploded view of the positive electrode plate of the secondary battery in the sixth embodiment of the present invention. 同実施の形態における負極板の展開図Development view of negative electrode plate in the same embodiment 同実施の形態における二次電池の構成を示す断面図Sectional drawing which shows the structure of the secondary battery in the same embodiment 従来のタブレス方式による二次電池を説明する図The figure explaining the secondary battery by the conventional tabless system 図10の二次電池の正極板の展開図FIG. 10 is a development view of the positive electrode plate of the secondary battery of FIG. 図10の二次電池の負極板の展開図FIG. 10 is a development view of the negative electrode plate of the secondary battery of FIG. 従来の二次電池の正極板の集電構造を説明する斜視図The perspective view explaining the current collection structure of the positive electrode plate of the conventional secondary battery 従来の二次電池の負極板の集電構造を説明する斜視図The perspective view explaining the current collection structure of the negative electrode plate of the conventional secondary battery

符号の説明Explanation of symbols

1 正極板
2 負極板
3 セパレータ(多孔質絶縁層)
4 電極群
5a 正極合剤未塗工部
5b 正極合剤塗工部
6a 負極合剤未塗工部
6b 負極合剤塗工部
7 内径保持部材
8 リング体
9 ばね材
10 正極集電部材
11 負極集電部材
12 電池容器
13 絶縁板
14 封口板
15 ガスケット
16 リブ
17 収縮リング体
18 締結部材
19 プッシュナット状リング体
20 突出部
21 補強層
DESCRIPTION OF SYMBOLS 1 Positive electrode plate 2 Negative electrode plate 3 Separator (porous insulating layer)
DESCRIPTION OF SYMBOLS 4 Electrode group 5a Positive electrode mixture uncoated part 5b Positive electrode mixture coated part 6a Negative electrode mixture uncoated part 6b Negative electrode mixture coated part 7 Inner diameter holding member 8 Ring body 9 Spring material 10 Positive electrode current collecting member 11 Negative electrode Current collecting member 12 Battery container 13 Insulating plate 14 Sealing plate 15 Gasket 16 Rib 17 Shrink ring body 18 Fastening member 19 Push nut-shaped ring body 20 Protruding portion 21 Reinforcing layer

Claims (7)

正極板および負極板の少なくとも一方の一端に設けた合剤未塗工部で示す集電体の露出部が多孔質絶縁層から突出するように、前記正極板と前記負極板と前記多孔質絶縁層とが捲回された電極群と、前記正極板および前記負極板に接続される集電部材と、
前記集電体の露出部の位置に設けた前記集電体の露出部の幅より小さい折れ曲がり防止部と、
を少なくとも有し、
前記折れ曲がり防止部として、
前記電極群の外周に嵌め込まれるリング体と捲回されている前記集電体の露出部の中間部に挿入される楔状のばね材とを用いたことを特徴とする二次電池。
The positive electrode plate, the negative electrode plate, and the porous insulation so that the exposed portion of the current collector shown by the mixture uncoated portion provided at one end of at least one of the positive electrode plate and the negative electrode plate protrudes from the porous insulating layer. and a is wound by electrode group layer, and collector member connected the positive electrode plate and the negative electrode plate,
A bending prevention portion smaller than the width of the exposed portion of the current collector provided at the position of the exposed portion of the current collector;
Having at least
As the bending prevention part,
A secondary battery comprising: a ring body fitted on an outer periphery of the electrode group; and a wedge-shaped spring material inserted into an intermediate portion of the exposed portion of the current collector wound.
正極板および負極板の少なくとも一方の一端に設けた合剤未塗工部で示す集電体の露出部が多孔質絶縁層から突出するように、前記正極板と前記負極板と前記多孔質絶縁層とが捲回された電極群と、前記正極板および前記負極板に接続される集電部材と、
前記集電体の露出部の位置に設けた前記集電体の露出部の幅より小さい折れ曲がり防止部と、
を少なくとも有し、
前記折れ曲がり防止部として、
前記電極群の前記集電体の露出部の外周部および内周部に嵌め込まれるリブを設けた前記集電部材で構成したことを特徴とする二次電池。
The positive electrode plate, the negative electrode plate, and the porous insulation so that the exposed portion of the current collector shown by the mixture uncoated portion provided at one end of at least one of the positive electrode plate and the negative electrode plate protrudes from the porous insulating layer. and a is wound by electrode group layer, and collector member connected the positive electrode plate and the negative electrode plate,
A bending prevention portion smaller than the width of the exposed portion of the current collector provided at the position of the exposed portion of the current collector;
Having at least
As the bending prevention part,
A secondary battery comprising the current collecting member provided with a rib fitted into an outer peripheral portion and an inner peripheral portion of an exposed portion of the current collector of the electrode group.
正極板および負極板の少なくとも一方の一端に設けた合剤未塗工部で示す集電体の露出部が多孔質絶縁層から突出するように、前記正極板と前記負極板と前記多孔質絶縁層とが捲回された電極群と、前記正極板および前記負極板に接続される集電部材と、
前記集電体の露出部の位置に設けた前記集電体の露出部の幅より小さい折れ曲がり防止部と、
を少なくとも有し、
前記折れ曲がり防止部として、
前記電極群の外周に嵌め込まれる収縮リング体を用い、前記収縮リング体の熱収縮により前記集電体の露出部を集合させることを特徴とする二次電池。
The positive electrode plate, the negative electrode plate, and the porous insulation so that the exposed portion of the current collector shown by the mixture uncoated portion provided at one end of at least one of the positive electrode plate and the negative electrode plate protrudes from the porous insulating layer. and a is wound by electrode group layer, and collector member connected the positive electrode plate and the negative electrode plate,
A bending prevention portion smaller than the width of the exposed portion of the current collector provided at the position of the exposed portion of the current collector;
Having at least
As the bending prevention part,
A secondary battery using a contraction ring body fitted on an outer periphery of the electrode group, and collecting exposed portions of the current collector by thermal contraction of the contraction ring body.
正極板および負極板の少なくとも一方の一端に設けた合剤未塗工部で示す集電体の露出部が多孔質絶縁層から突出するように、前記正極板と前記負極板と前記多孔質絶縁層とが捲回された電極群と、前記正極板および前記負極板に接続される集電部材と、
前記集電体の露出部の位置に設けた前記集電体の露出部の幅より小さい折れ曲がり防止部と、
を少なくとも有し、
前記折れ曲がり防止部として、
前記電極群の外周に装着された締結部材を用い、前記締結部材の締結により前記集電体の露出部を集合させることを特徴とする二次電池。
The positive electrode plate, the negative electrode plate, and the porous insulation so that the exposed portion of the current collector shown by the mixture uncoated portion provided at one end of at least one of the positive electrode plate and the negative electrode plate protrudes from the porous insulating layer. and a is wound by electrode group layer, and collector member connected the positive electrode plate and the negative electrode plate,
A bending prevention portion smaller than the width of the exposed portion of the current collector provided at the position of the exposed portion of the current collector;
Having at least
As the bending prevention part,
A secondary battery comprising: a fastening member mounted on an outer periphery of the electrode group; and collecting the exposed portions of the current collector by fastening the fastening member.
正極板および負極板の少なくとも一方の一端に設けた合剤未塗工部で示す集電体の露出部が多孔質絶縁層から突出するように、前記正極板と前記負極板と前記多孔質絶縁層とが捲回された電極群と、前記正極板および前記負極板に接続される集電部材と、
前記集電体の露出部の位置に設けた前記集電体の露出部の幅より小さい折れ曲がり防止部と、
を少なくとも有し、
前記折れ曲がり防止部として、
プッシュナット状リング体を電極群の外周に装着し、前記プッシュナット状リング体の内周に設けられた複数個の突出部で前記集電体の露出部を集合させることを特徴とする二次電池。
The positive electrode plate, the negative electrode plate, and the porous insulation so that the exposed portion of the current collector shown by the mixture uncoated portion provided at one end of at least one of the positive electrode plate and the negative electrode plate protrudes from the porous insulating layer. and a is wound by electrode group layer, and collector member connected the positive electrode plate and the negative electrode plate,
A bending prevention portion smaller than the width of the exposed portion of the current collector provided at the position of the exposed portion of the current collector;
Having at least
As the bending prevention part,
A secondary structure characterized in that a push nut-shaped ring body is mounted on an outer periphery of an electrode group, and an exposed portion of the current collector is assembled by a plurality of protrusions provided on an inner periphery of the push nut-shaped ring body. battery.
正極板および負極板の少なくとも一方の一端に設けた合剤未塗工部で示す集電体の露出部が多孔質絶縁層から突出するように、前記正極板と前記負極板と前記多孔質絶縁層とが捲回された電極群と、前記正極板および前記負極板に接続される集電部材と、
前記集電体の露出部の位置に設けた前記集電体の露出部の幅より小さい折れ曲がり防止部と、
を少なくとも有し、
前記折れ曲がり防止部として、
前記正極板および前記負極板の前記集電体の露出部と、前記正極板および前記負極板の合剤塗工部との境界部の全てに補強層を設けたことを特徴とする二次電池。
The positive electrode plate, the negative electrode plate, and the porous insulation so that the exposed portion of the current collector shown by the mixture uncoated portion provided at one end of at least one of the positive electrode plate and the negative electrode plate protrudes from the porous insulating layer. and a is wound by electrode group layer, and collector member connected the positive electrode plate and the negative electrode plate,
A bending prevention portion smaller than the width of the exposed portion of the current collector provided at the position of the exposed portion of the current collector;
Having at least
As the bending prevention part,
A secondary battery comprising a reinforcing layer at all boundary portions between the exposed portion of the current collector of the positive electrode plate and the negative electrode plate and a mixture coating portion of the positive electrode plate and the negative electrode plate .
前記折れ曲がり防止部として、
前記電極群に内径保持部材を設けたことを特徴とする請求項1から請求項6のいずれか1項に記載の二次電池。
As the bending prevention part,
The secondary battery according to any one of claims 1 to 6, wherein an inner diameter holding member is provided in the electrode group.
JP2007539394A 2006-06-02 2007-05-24 Secondary battery Expired - Fee Related JP4835594B2 (en)

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